Long before calendar watches, our schedules and our habits were formed from the moment our forefathers looked up into the sky and observed the passing of time through the movements of the sun, the moon and the stars.
The calendar we all know today, divided into 24 hour days, seven days a week, and 28, 29, 30 or 31 days a month to total 365 days a year was created in the year 1582 by Pope Gregory XIII. And five centuries later, we’re still using the same system, though it’s not without its faults. Three hundred and sixty-five days actually falls slightly short of the solar year of 365.24667 days (the time it takes the Earth to make one revolution around the sun). To make up for this difference, February 29 is added once every four years, but taken out every 100 years.
This is why horology is so fascinating: clockmakers first found a way to make calendar clocks, then miniaturised the mechanism so it could fit in your pocket, and then miniaturised it some more so it was small enough to wear on the wrist. Calendar watches range from those with the more simple date-only function to the most complex perpetual-calendar complication, which could keep track of time, day, date, months, down to the leap year, without requiring manual adjustments for more than 100 years.
Starting with the simplest of calendar complications is the date-only timepiece, which comes with a date wheel with increments daily from 1 to 31, requiring correction every other month for the months with fewer than 31 days. The most common way to tell the date is by the window display, usually positioned at 3 o’clock or 6 o’clock. A Lange & Söhne has made the oversized date its signature, presenting the numbers in two separate, single-digit windows on the dial that are extremely easy to read. The oversized date is used for every watch within the Lange 1 family. In 2018, Lange also re-introduced the oversized date into its Saxonia collection, in tribute to the original Saxonia model first released in 1994, one of four watches that were debuted with the re-establishment of the manufacture that year.
The day-date function, also known as the double-date complication, is one which essentially tells the day of the week and the date, in addition to the time. The most famous is undisputedly the Rolex Oyster Perpetual Day-Date. At its launch in 1956, the Rolex Day-Date marked a significant moment in horological history. It was the first calendar wristwatch to spell out the day of the week in full, and it would cement a particular day-date aesthetic for decades to come. The date display, as on many Rolex models, is magnified by a Cyclops lens on the crystal. The Day-Date is made in precious metals only and is the watch of choice for many of the world’s most influential figures – an ultimate status symbol, it’s nicknamed the “Presidents’ watch”. The line-up today includes models in both 36mm and 40mm, with a wide-ranging variety of coloured dials, but all in precious metals and on the popular President bracelet. The most famous and coveted is, of course, the all gold Day-Date on the President bracelet. Pictured here in 40mm, the watch is equipped with the self-winding 3255 certified Superlative Chronometer calibre with a power reserve of 70 hours.
At one point in time, the complete calendar was pretty commonplace – also called the triple calendar, the watch provided the date, day and month, sometimes including a moon phase or other complications such as the chronograph. Movement maker Valjoux supplied the calibre 72C (triple-date chronograph) and 88 (triple- date chronograph with moon phase) from the 1940s to the 60s’ to many watch companies, establishing the look of the complete-calendar watch of that era. Both Valjoux movements were compact, displaying the day and month on two windows at 12 o’clock and the date via a pointed hand around the perimeter of the dial. This configuration could also be seen on more prestigious models, such as the vintage Rolex ref. 4767 “Jean-Claude Killy” as well as annual-calendar watches from Patek Philippe and Vacheron Constantin in that era.
The popularity of the triple calendar waned as people turned to the more complex and convenient annual and perpetual calendars, but there’s still a certain charm to this retro complication. Vacheron Constantin certainly must have thought so too, when it decided to bring back the complication in its Historiques collection. Inspired by the reference 4240, the Historiques Triple Calendrier 1942 reflects the design codes of the original model but with a contemporary twist. The Triple Calendrier 1942 bears the same hours, minutes and small seconds at 6 o’clock, along with the date shown by a central hand with a red arrow-head pointer. The day and month are shown in two apertures at 12 o’clock. The distinctive “triple gadroon” caseband with claw-type lugs are also typical of the era. Made in steel, the watch is topped by a box- type glass and is water-resistant to 3 bar. The calibre within is the manual-winding 4400 QC, beating at a frequency of 4Hz, with a power reserve of 65 hours.
Jaeger-LeCoultre, renowned for its triple-calendar watches in the ’40s and ’50s, has also released a major update to its Master Control Calendar this year, which is now equipped with its new calibre 866. The movement now comes with an extended power reserve of 70 hours, thanks to an improved mainspring and barrel. The date display has also been improved: as the red-tipped date hand switches from the 15th to the 16th of the month, it jumps 90-degrees to avoid obscuring the moon phase display.
Special mention must go to Patek Philippe’s Weekly Calendar ref. 5212A-001, which turned heads in 2019 when it was launched during Baselworld. The watch is like a triple calendar, but with a new purpose – the week is the focus here. It’s also cased in stainless steel, a departure from the precious metals preferred on the Calatrava. The 5212A, in addition to displaying the day of the week and date, also shows the number of weeks in the year in accordance with the ISO 8610 standard, where the first official week of the year begins on the Monday of the week of January 4. On the dial, the date is indicated in the window positioned at 3 o’clock, the day is shown by a short red-tipped hand at the centre of the dial, and the week and month indicated by a longer red tipped hand around the outer edge of the dial. The date is corrected through the crown, and the weekday and the week-number indications are controlled via two correctors in the case flank. A special movement – the self-winding calibre 26-330, which beats at a frequency of 4Hz with a maximum power reserve of 45 hours – was created for this unusual watch. Another detail we love is the handwritten typography, which provides a wonderful sense of whimsy and an almost vintage air to the otherwise practical and functional watch.
You could think of the annual calendar function as one that closes the gap between the simple date display and the highly complex perpetual calendar. The annual calendar is as practical as it gets, and at a fraction of the price of the more sophisticated perpetual calendar. Simpler calendar watches would require five adjustments a year (provided that the watch doesn’t stop running) to accurately display the date. The annual calendar watch will automatically adjust the date displayed at the end of each month. The only manual adjustment required is in February, when the month cycle is only 28 days. There are many variations of the annual calendar on the market today – Patek Philippe has several models in different configurations, while Rolex, with the Oyster Perpetual Sky-Dweller, has completely redefined what an annual-calendar complication can look like.
One with a practical look that makes reading the calendar extremely easy at a glance is the IWC Portugieser Annual Calendar.
Debuted in 2015, the watch is fitted with the IWC-manufactured 52850 calibre, equipped with twin barrels to supply the watch with a whopping seven-day power reserve. On the Portugieser Annual Calendar, the annual calendar shows the month, date and day in three separate, curved windows. Its straightforward layout – in an “American” order in homage to IWC’s American founder, FA Jones – makes reading the calendar extremely easy, all the information is comprehensible at a glance, and the large case size, at 44.2mm, also makes reading the dial easy. While the watch requires manual adjustment once every year at the end of February, IWC’s designers have made this as fuss-free as possible, as it’s easily and conveniently carried out using the crown without the need of an additional corrector.
And now we come to the most complex and most revered of calendar complications, the perpetual calendar. The perpetual-calendar mechanism is able to keep track of the day, date, taking into account the shifting 30 and 31-day cycles, know when it’s February when it has only 28 days, as well as knowing that every four years, February has 29 days. The first watchmaker to put this complication into a pocket watch was Thomas Mudge in 1762 but it wasn’t until 1925 that Patek Philippe miniaturised the complication successfully, and almost 20 years after that for it to produce the perpetual-calendar wristwatch in series with the legendary ref. 1526 in 1941.
Audemars Piguet first produced a perpetual calendar wristwatch in 1978, in the midst of the Quartz Crisis. The successful launch of the calibre 2120/2800 marked a milestone for the brand, propelling it down a path of creating complicated wristwatches at a time when mass-produced quartz technology threatened to decimate the mechanical watchmaking industry. Maybe this compelling story is the reason why the perpetual-calendar wristwatch enjoys the status it does today. It’s the ultimate grail watch for many collectors, as well as a mark of a watchmaker’s excellence – perhaps it’s for this reason that perpetual calendars are the most complicated calendar watches to produce, and also the most contemporary in looks. While simpler calendar watches often retain a more classical, even vintage aesthetic, perpetual calendars of today are extremely robust and avant-garde in look and feel, constantly pushing the limits of watchmaking with launch after launch of impressive mechanical feats.
Audemars Piguet presented the Royal Oak Selfwinding Perpetual Calendar Ultra-Thin in 2019, based on a concept model, the RD#2, that was introduced the year before. To date, it’s the thinnest automatic perpetual-calendar ever produced, housed inside AP’s familiar Royal Oak case. The watch is 41mm in diameter, but only 6.3mm in height – 3.2mm thinner than a regular Royal Oak Perpetual Calendar, which in itself is already a pretty slim watch. To make the calendar indications easier to read, Audemars Piguet has done away with the classic “petite tapisserie” guilloché pattern on the typical Royal Oak. The watch is also in titanium, making it incredibly lightweight on the wrist.
One of the latest perpetual calendar models released this year is MB&F’s Legacy Machine Perpetual Evo, which celebrates the brand’s 15th anniversary. With the word Evo in its name, the watch is enhanced with a zirconium case, a rubber strap and a screw-down crown, giving it a water resistance of up to 80 metres. The perpetual- calendar movement is also protected by a mono-block shock protection system called “FlexRing”, a damper that protects all the watch’s 581 parts from the usual rigours of life. Three versions of this watch are available in a very limited 15 orders each, but the one that’s caught our eye is the blue PVD version.